Measure Interobserver Agreement Research Articles

Does a Combination of Two Radiographs Increase Accuracy in Detecting Acid-induced Periapical Lesions and Does It Approach the Accuracy of Cone-Beam Computed Tomography Scanning?

Introduction The purpose of this study was to determine whether the use of a combination of 2 images (storage phosphor plates [SPPs] and F-speed films [Eastman Kodak, Rochester, NY]) with a 10° difference in horizontal beam angulation resulted in better detectability of chemically created periapical defects than when only 1 image was used and whether a detectability as good as that achieved by limited cone-beam computed tomography (LCBCT) scanning could be achieved. Methods Lesions were created by 1, 1.5, and 2 hours of acid application apical to extracted teeth in jaw specimens. After repositioning, teeth were radiographed with Accu-I-Tomo LCBCT, Digora Optime SPP system, and F-speed films. The SPPs and films were exposed at 0° and 10° horizontal angulations. The diagnostic accuracy (Az) was compared using 2-way analysis of variance; pair-wise comparisons were performed using the post hoc t test. Kappa was used to measure interobserver agreement. Results A combination of 2 exposures with a 10° difference in horizontal angulation caused an increase, although not statistically significant, in the accuracy of both films and SPPs for all acid durations ( P > .05) compared with when only 1 exposure was used. The accuracy did not approach that of LCBCT. Conclusions Using a combination of 2 exposures instead of 1 did not significantly increase the accuracy in detecting acid-induced lesions at the apices of single-rooted premolars. The accuracy of LCBCT was superior.

Concordancia entre dos observadores en la medición del consumo de tabaco y del uso del cinturón de seguridad y del teléfono móvil en vehículos

The aim of this study was to assess the feasibility of direct observations of smoking and use of seat belts and cell phones in drivers in the city of Barcelona, and to analyze the agreement between two observers. We performed 315 pairs of observations. The simple percentage inter-observer agreement between driver and passenger smoking was 100% with a Kappa coefficient=1.0. There was high inter-observer agreement in measurement of cell phone use and the number of passengers aged less than 14 years old. The variable with the lowest agreement was the driver's age. In conclusion, direct observation studies are a good resource for monitoring smoking and use of seat belts and cell phones in the drivers of motor vehicles.

Three-dimensional measurements of the lower extremity in children and adolescents using a low-dose biplanar X-ray device

To evaluate three-dimensional (3D) measurements of the lower extremity using a biplanar low-dose X-ray device in children and adolescents. Firstly, 3D measurements of eight dried bones were analysed by a biplanar low-dose X-ray device (LDX) using stereoscopic software and compared with 3D computed tomography (CT). Secondly, 47 lower limbs of children and adolescents were studied using LDX two-dimensional (2D) and 3D measurements. Both parts were evaluated for femoral and tibial lengths and mechanical angles, frontal and lateral knee angulations, and the femoral neck-shaft angle. The 3D specimen comparison between LDX and CT measurements showed no significant differences: femoral length (P = 0.069), tibial length (P = 0.059), femoral mechanical angle (P = 0.475), tibial mechanical angle (P = 0.067), frontal knee angulation (P = 0.198), lateral knee angulation (P = 0.646) and femoral neck-shaft angle (P = 0.068). The comparison between LDX 2D and 3D measurements showed significant differences in tibial length (P = 0.003), femoral mechanical angle (P < 0.001) and femoral neck-shaft angle (P = 0.001); other parameters were unremarkable. The 3D LDX system presented reliable measurements compared with 3D CT. Differences between LDX 2D and 3D measurements were noted in the femoral mechanical angle, femoral neck-shaft angle and tibial length. Moderate to good interobserver agreement for the 3D LDX measurements were found. Low radiation dose is essential when assessing potential lower extremity discrepancies. A new biplanar low-dose X-ray device can assess such discrepancies in children/adolescents. This LDX device provides equally reliable 3D measurements as prevalent practice LDX measurements carry good overall interobserver agreement.

Evaluation of acute infection-induced endothelial dysfunction and its potential mediators

Objectives Infl ammation plays an important role in the pathophysiology of atherosclerosis. Some studies suggest a link between chronic infections, an infl ammatory state, and endothelial dysfunction. However, data related to acute infections are scant. We have investigated: (i) the eff ect of acute infection on endothelial function; (ii) the role of potential mediators of endothelial dysfunction.Methods Forty patients ≥ 40 years old with acute infection (mean age 53.9 ± 8.8 years), without coronary artery disease or its equivalents were enrolled. Endothelial function and blood levels of high sensitive C-reactive protein, interleukin-6, tumour necrosis factor-α, high-density lipoprotein cholesterol (HDL), low-density lipoprotein cholesterol (LDL), apolipoprotein-A1 (Apo-A1) and apolipoprotein-B100 (Apo-B100) were assessed in the acute infection phase and 1 month after recovery. Endothelial function was evaluated by brachial artery fl ow-mediated vasodilation (FMD).Results The intraclass correlation coeffi cients for intra- and interobserver agreement for FMD measurements were 0.98 (95% CI: 0.95-0.99) and 0.93 (95% CI: 0.83-0.97), respectively. FMD improved signifi cantly 1 month after recovery (P < 0.001). Compared to the levels at 1 month, infl ammatory markers, LDL cholesterol, LDL/HDL ratio, Apo-B100 and Apo-B100/Apo-A1 ratio were signifi cantly higher. However, HDL and apo-A1 were signifi cantly lower in the phase of acute infection. Change in FMD from baseline to 1 month after recovery correlated signifi cantly only with the change in Apo-A1 (r = 0.35, P= 0.027).Conclusions Acute infection causes transient endothelial dysfunction. It increases infl ammatory markers and generates an atherogenic lipid profi le. Among the parameters evaluated, only the change in Apo-A1 level was associated with acute infection-induced endothelial dysfunction.

The use of digital images to evaluate the interobserver agreement on cervical smear readings in Italian cervical cancer screening

The aim of this study was to measure interobserver agreement among cytologists on using a set of digital images. A set of 90 selected Papanicolaou-stained cervical smears were digitalized and the digital images circulated among 117 readers, from laboratories spread across almost all Italian regions. Three representative fields of each smear were displayed at 20× and 40× magnification (overall six images for each case). The diagnoses made by the cytologists who provided the images were taken as target diagnoses. The κ values were: very low for the categories atypical squamous cells of undetermined significance (ASC-US), and atypical squamous cells - cannot exclude high-grade squamous intraepithelial lesion (ASC-H); poor for the categories atypical glandular cells (AGC), high-grade squamous intraepithelial lesion (HSIL) and invasive cancer; and fair to good for the categories negative and low-grade squamous intraepithelial lesion (LSIL). However, we found a cluster of 42 best concordant readers. The overall κ value and overall weighted κ with the target diagnosis for these 42 readers were 0.45 and 0.66, respectively. This finding is in contrast with the overall κ value and overall weighted κ for the other readers of 0.39 and 0.59, respectively. As this finding is an estimate of the accuracy of the readers, we can infer that it will be very important to reach this level of concordance for all the participating readers. Future effort will facilitate common experiences in order to improve the reproducibility of diagnostic criteria. Digital images could be the key to reach this aim.

Whole tumour first-pass perfusion using a low-dose method with 64-section multidetector row computed tomography in oesophageal squamous cell carcinoma

To propose a low-dose method at tube current-time product of 50 mAs for whole tumour first-pass perfusion of oesophageal squamous cell carcinoma using 64-section multidetector row computed tomography (MDCT), and to assess the original image quality and accuracy of perfusion parameters. Fifty-nine consecutive patients with confirmed oesophageal squamous cell carcinomas were enrolled into our study, and underwent whole tumour first-pass perfusion scan with 64-section MDCT at 50 mAs. Image data were statistically reviewed focusing on original image quality demonstrated by image-quality scores and signal-to-noise (S/N) ratios; and perfusion parameters including perfusion (PF, in ml/min/ml), peak enhanced density (PED, in HU), time to peak (TTP, in seconds) and blood volume (BV, in ml/100 g) for the tumour. To test the interobserver agreement of perfusion measurements, perfusion analyses were repeatedly performed. Original image-quality scores were 4.71±0.49 whereas S/N ratios were 5.21±2.05, and the scores were correlated with the S/N ratios (r=0.465, p<0.0001). Mean values for PF, PED, TTP and BV of the tumour were 33.27±24.15 ml/min/ml, 24.06±9.87 HU, 29.42±8.61 s, and 12.45±12.22 ml/100 g, respectively. Intraclass correlation coefficient between the replicated measurements of each perfusion parameter was greater than 0.99, and mean difference of the replicated measurements of each parameter was close to zero. Whole tumour first-pass perfusion with 64-section MDCT at low-dose radiation could be reproducible to assess microcirculation in oesophageal squamous cell carcinoma without compromising subjective original image quality of the tumour.

Utility of diffusion‐weighted MRI in distinguishing benign and malignant hepatic lesions

To evaluate apparent diffusion coefficient (ADC) values for characterization of a variety of focal liver lesions and specifically for differentiation of solid benign lesions (focal nodular hyperplasia [FNH] and adenomas) from solid malignant neoplasms (metastases and hepatocellular carcinoma [HCC]) in a large case series. A total of 542 lesions in 382 patients were evaluated. ADC values were measured in 166 hemangiomas, 112 hepatomas, 107 metastases, 95 cysts, 10 abscesses, 43 FNH, and nine adenomas. ADCs of 1.5 and 1.6 (x10(-3) mm(2)/second) were selected as threshold values to separate benign and malignant lesions. Sensitivity, specificity, positive, and negative predictive values (PPV, NPV) were calculated. Comparisons were carried out with studentized range test. There was high interobserver agreement in ADC measurements for all lesion types. The mean ADCs for cysts was 3.40 (x10 (-3) mm(2)/second), hemangiomas 2.26, FNH 1.79, adenomas 1.49, abscesses 1.97, HCC 1.53, and metastases 1.50. The mean ADC for benign lesions was 2.50 and for malignant lesions was 1.52. Cysts were easily distinguished from other lesions. There was, however, overlap between solid benign and malignant lesions. Benign lesions have higher mean ADC values than malignant lesions. However, ADC values of solid benign lesions (FNH and adenomas) are similar to malignant lesions (metastases, HCC) limiting the value of diffusion weighted imaging (DWI) for differentiating solid liver masses.

Improved Differentiation of Benign Osteochondromas from Secondary Chondrosarcomas with Standardized Measurement of Cartilage Cap at CT and MR Imaging

To validate a technique for reproducible measurement of the osteochondroma cartilage cap with computed tomography (CT) and magnetic resonance (MR) imaging and to reevaluate the correlation of the thickness of the cartilage cap with pathologic findings to improve noninvasive differentiation of benign osteochondromas from secondary chondrosarcomas. The institutional review board approved the study and waived the need for informed consent. HIPAA compliance was maintained. After validation of the measurement technique, 101 pathologically confirmed osteochondromas were retrospectively reviewed. Patient demographic data, histologic diagnosis, and chondrosarcoma grade were recorded. Two musculoskeletal radiologists used a standardized technique to independently measure the thicknesses of the cartilage caps on CT and MR images; these measurements were compared for interobserver agreement. Agreement between measurements with CT and MR imaging was also evaluated, as were the sensitivity and specificity of both modalities for differentiation of osteochondromas from chondrosarcomas. Evaluated were 67 benign osteochondromas (from 49 male patients and 18 female patients; mean age, 23.4 years) and 34 secondary chondrosarcomas (from 27 male patients and seven female patients; mean age, 33.2 years). On the basis of the proposed measuring technique, there was 88% interobserver measurement agreement with MR imaging (95% confidence interval [CI]: 80%, 94%) and 93% with CT (95% CI: 84%, 98%). The median difference between measurements of cap thickness at CT and MR imaging was 0 cm (25th and 75th percentiles, -3 mm and 1 mm, respectively). With 2 cm used as a cutoff for distinguishing benign osteochondromas from chondrosarcomas, the sensitivities and specificities were 100% and 98% for MR imaging and 100% and 95% for CT, respectively. The proposed measuring technique allows accurate and reproducible measurement of cartilage cap thickness with both CT and MR imaging. Cap thickness of 2 cm or greater strongly indicated secondary chondrosarcomas.

Three-dimensional volume-rendering technique in the angiographic follow-up of intracranial aneurysms embolized with coils

The authors conducted a study to evaluate the advantages of a 3D volume-rendering technique (VRT) in follow-up digital subtraction (DS) angiography of coil-embolized intracranial aneurysms. One hundred nine patients with 121 intracranial aneurysms underwent endovascular coil embolization and at least 1 follow-up DS angiography session at the authors' institution. Two neuroradiologists independently evaluated the conventional 2D DS angiograms, rotational angiograms, and 3D VRT images obtained at the interventional procedures and DS angiography follow-up. If multiple follow-up sessions were performed, the final follow-up was mainly considered. The authors compared the 3 techniques for their ability to detect aneurysm remnants (including aneurysm neck and sac remnants) and parent artery stenosis based on the angiographic follow-up. The Kruskal-Wallis test was used for group comparisons, and the kappa test was used to measure interobserver agreement. Statistical analyses were performed using commercially available software. There was a high statistical significance among 2D DS angiography, rotational angiography, and 3D VRT results (X(2) = 9.9613, p = 0.0069) when detecting an aneurysm remnant. Further comparisons disclosed a statistical significance between 3D VRT and rotational angiography (X(2) = 4.9754, p = 0.0257); a high statistical significance between 3D VRT and 2D DS angiography (X(2) = 8.9169, p = 0.0028); and no significant difference between rotational angiography and 2D DS angiography (X(2) = 0.5648, p = 0.4523). There was no statistical significance among the 3 techniques when detecting parent artery stenosis (X(2) = 2.5164, p = 0.2842). One case, in which parent artery stenosis was diagnosed by 2D DS angiography and rotational angiography, was excluded by 3D VRT following observations of multiple views. The kappa test showed good agreement between the 2 observers. The 3D VRT is more sensitive in detecting aneurysm remnants than 2D DS angiography and rotational angiography and is helpful for identifying parent artery stenosis. The authors recommend this technique for the angiographic follow-up of patients with coil-embolized aneurysms.

Role of Sonographic Automatic Volume Calculation in Measuring Fetal Cardiac Ventricular Volumes Using 4-Dimensional Sonography

The purpose of this study was to compare the agreement and reliability of virtual organ computer-aided analysis (VOCAL) and sonographic automatic volume calculation (sonoAVC) for measurements of ventricular volume from fetal heart data sets acquired by 4-dimensional sonography with spatiotemporal image correlation (STIC). We studied 45 volumes from fetuses with normal (n = 30) and abnormal (n = 15) hearts. Spatiotemporal image correlation data sets were frozen in end systole and end diastole, and ventricular volumes were measured with VOCAL and sonoAVC. The stroke volume was calculated from these measurements. Reliability and agreement of the two techniques were evaluated with intraclass correlation coefficients (ICCs), and proportionate Bland-Altman plots were constructed. The time necessary to complete the measurements with either technique was compared. Intraobserver and interobserver agreement of measurements was calculated. All data sets could be measured with both techniques. A high degree of reliability was observed between VOCAL and sonoAVC (left ventricular stroke volume ICC, 0.978; 95% confidence interval [CI], 0.957-0.989; right ventricular stroke volume ICC, 0.985; 95% CI, 0.972-0.992). The time necessary to measure the stroke volume was significantly shorter with sonoAVC (2.8 versus 11.7 minutes; P < .0001) than with VOCAL. Bland-Altman tests showed no clinically significant mean percent differences between stroke volume measurements obtained from each ventricle by the same observer or by 2 independent observers using either VOCAL or sonoAVC. There was good agreement between cardiac volumes measured with VOCAL and sonoAVC. Sonographic automatic volume calculation represents a rapid technique for estimating fetal stroke volume and promises to become the method of choice.

Evaluación de un protocolo de predicción de vía aérea difícil en la práctica habitual: estudio de concordancia

To evaluate a protocol for routine assessment of potential risk factors for difficult airway intubation in an anesthesia department, by measuring interobserver agreement and the behavior of the factors in a predictive model. A cross-sectional study group of 320 consecutive patients undergoing major surgery requiring orotracheal intubation was assessed for possible difficult airway. We calculated interrater agreement for recording of the Mallampati score, thyromental distance less than 6 cm, thick neck, kyphosis, small mouth, macroglossia, and dental prosthesis during the preanesthesia examination (by an anesthetist) and on the day of the operation (by an anesthetist and a resident). We constructed a model to predict difficult intubation (requiring 3 or more attempts). The kappa indices of agreement between the anesthetists at the preoperative examination and in the operating room or the resident were all less than 0.6. Factors like thyromental distance, small mouth, and kyphosis had kappa indices less than 0.21. The kappa index between the resident and the anesthetist in the operating room was over 0.55. The only factor that had a different level of agreement was the presence or not of a dental prosthesis. None of the studied individual factors, nor these factors in association with the Mallampati score, achieved significance in a bivariate regression model to predict difficult intubation. There is poor interobserver agreement on factors for predicting difficult airway in comparisons between preoperative and operating room assessment by an anesthetist or a resident. The individual predictive factors and their association with the Mallampati score did not prove useful for predicting difficult intubation.

Defects on endoanal ultrasound and anal incontinence after primary repair of fourth‐degree anal sphincter rupture: a study of the anal sphincter complex and puborectal muscle

To perform three-dimensional endoanal ultrasound (EAUS) after primary repair of fourth-degree anal sphincter rupture (ASR) and correlate the sonographic defects with anal incontinence (AI); to measure the axial and sagittal thickness and angle of the puborectal muscle (PRM) as well as the length of the anal canal, and then correlate these measures with AI; and to assess the interobserver measurement agreement between an inexperienced and an experienced sonologist. EAUS was offered to 84 consecutive women, who were asked to answer a validated questionnaire after fourth-degree ASR. AI was graded according to the Wexner score and EAUS defects were graded according to the Starck score. Sixty-one women (73%) answered the questionnaire. The median (range) follow-up time was 5.1 (1.3-8.7) years. Thirty-three (54%) of these women underwent EAUS and were included in the study. There was no difference in the incontinence scores between women who underwent EAUS and those who did not. Eleven of the women who underwent EAUS (33%) were continent, 22 women (67%) had flatus incontinence at least once a month, of whom 12 also had incontinence for liquid stool and two had incontinence for solid stool. The median Wexner score was 2 (range, 0-12). Five of the patients (15%) had no ultrasound defects. All of the patients with Wexner scores > or = 4 had a Starck score of > or = 10. No association between ultrasound defects and AI was demonstrated, however, the angle of the PRM and parity were associated with Starck score. No clear association between the measurements of the PRM and AI was shown. The experienced observer detected more of the small defects than did the inexperienced observer. In a 1-9-year follow-up period after primary suture of fourth-degree ASR, the frequency of AI was high, at 67%. No clear association was seen between AI and sphincter defects detected on ultrasonography. There was an association between the angle of the PRM and the extent of ultrasound defects.

Defining juxtapapillary diverticulum with 3D segmented trueFISP MRCP: comparison with conventional MRCP sequences with an oral negative contrast agent

To compare three-dimensional segmented true fast imaging with steady-state precession magnetic resonance cholangiopancreatography (3D-trueFISP-MRCP) to conventional MRCP sequences with an oral negative contrast agent for diagnosing juxtapapillary diverticulum. A total of 42 patients with (n = 21) and without (n = 21) juxtapapillary diverticulum confirmed by endoscopic retrograde cholangiopancreatography (ERCP) were evaluated. Three MRCP sequences, 3D-trueFISP-MRCP, two-dimensional rapid acquisition with relaxation enhancement MRCP (2D-RARE-MRCP), and 3D T(2)-weighted turbo spin-echo MRCP (3D-TSE-MRCP), obtained after administering an oral negative contrast agent (FerriSeltz; Otsuka Pharmaceutical, Tokushima, Japan) were compared. Two radiologists independently and blindly interpreted the presence or absence of juxtapapillary diverticulum and its positional relationship against the papilla. The detectability of juxtapapillary diverticulum of each sequence as decided by consensus was then compared. Kappa statistics were used to measure interobserver agreement of the classifications. The sensitivity, specificity, and accuracy for detecting juxtapapillary diverticulum of 3D-trueFISPMRCP (61.9%, 85.7%, and 73.8%) were substantively higher than those of 2D-RARE-MRCP (0.0%, 100%, and 50.0%) and 3D-TSE-MRCP (9.5%, 100%, and 54.8%). Interobserver agreement of the position of juxtapapillary diverticulum by 3D-trueFISP-MRCP was good (kappa = 0.55). 3D-trueFISP-MRCP can define juxtapapillary diverticulum even with an oral negative contrast agent, whereas conventional MRCP sequences cannot.

A retrospective study of the MRI findings in 18 dogs with stifle injuries

To make an objective assessment of the usefulness of magnetic resonance imaging in the diagnosis of meniscal damage and cranial cruciate ligament disease in the canine stifle by comparing magnetic resonance imaging findings with surgical findings. Magnetic resonance images of 18 stifles from 18 dogs which had undergone magnetic resonance imaging for the investigation of stifle disease were reviewed. For every stifle, the menisci and cranial cruciate ligaments were assessed according to predetermined criteria. The magnetic resonance imaging findings were compared with the reported surgical findings and the sensitivity, specificity, positive and negative predictive values (PPV and NPV) were calculated using the surgical findings as the gold standard. Kappa analysis was used as an objective measure of agreement between surgical and magnetic resonance imaging findings. For 11 stifles, meniscal evaluation by three different observers was used to measure interobserver agreement using Kappa analysis. Magnetic resonance imaging was demonstrated to be an accurate technique in the detection of meniscal injury (k=0.86), with excellent interobserver agreement (k=0.89 to 1.0). Disruption of cranial cruciate ligament continuity and an increase in ligament intensity were found to be useful criteria in the diagnosis of cranial cruciate ligament rupture. Magnetic resonance imaging offers a non-invasive alternative to exploratory surgery in the evaluation of cranial cruciate ligament and meniscal disease.

Placental Vascular Sonobiopsy Using Three-dimensional Power Doppler Ultrasound in Normal and Growth Restricted Fetuses

Objective To investigate placental vascular sonobiopsy using three-dimensional (3D) power Doppler ultrasound to assess placental vascularization in normal and growth restricted fetuses. Methods Placental vascular sonobiopsy using 3D power Doppler ultrasound with the VOCAL imaging analysis program was performed on 208 normal fetuses between 12 and 40 weeks of gestation and 13 pregnancies with fetal growth restriction (FGR) at 22–39 weeks' gestation. Only pregnancies with an entirely visualized anterior placenta were included in the study. 3D power Doppler indices related to placental vascularization (vascularization index (VI), flow index (FI) and vascularization flow index (VFI)) were calculated in each placenta. Intra- and inter-class correlation coefficients and intra- and inter-observer agreements of measurements were assessed. Results A weak linear relationship was found between the gestational age and VI, FI, and VFI, respectively. VI values in 8 of 13 FGR pregnancies (61.5%), FI value in one FGR pregnancy (7.7%) and VFI values of 6 FGR pregnancies (46.2%) were below −1.5SD of the reference ranges for VI, FI and VFI, respectively. After 32 weeks of gestation, VI, FI, and VFI values in 10 FGR pregnancies were significantly lower compared to 79 normal pregnancies, respectively ( P < 0.01). All 3D power Doppler indices (VI, FI and VFI) showed a correlation greater than 0.85, with good intra- and inter-observer agreements. Conclusion Our findings suggest that placental vascular sonobiopsy using 3D power Doppler ultrasound may provide new information on the assessment of placental vascularization in normal and FGR pregnancies, while placental perfusion is reduced in FGR compared to normal pregnancy. However, the data and its interpretation in our study should be taken with some degree of caution because of the small number of FGR subjects studied. Further studies involving a larger sample size of FGR pregnancies are needed to confirm the usefulness of placental vascular sonobiopsy using 3D power Doppler ultrasound in clinical practice.

Automated versus manual post-processing of perfusion-CT data in patients with acute cerebral ischemia: influence on interobserver variability

IntroductionThe purpose of this study is to compare the variability of PCT results obtained by automatic selection of the arterial input function (AIF), venous output function (VOF) and symmetry axis versus manual selection.MethodsImaging data from 30 PCT studies obtained as part of standard clinical stroke care at our institution in patients with suspected acute hemispheric ischemic stroke were retrospectively reviewed. Two observers performed the post-processing of 30 CTP datasets. Each observer processed the data twice, the first time employing manual selection of AIF, VOF and symmetry axis, and a second time using automated selection of these same parameters, with the user being allowed to adjust them whenever deemed appropriate. The volumes of infarct core and of total perfusion defect were recorded. The cerebral blood volume (CBV), cerebral blood flow (CBF), mean transit time (MTT) and blood–brain barrier permeability (BBBP) values in standardized regions of interest were recorded. Interobserver variability was quantified using the Bland and Altman's approach.ResultsAutomated post-processing yielded lower coefficients of variation for the volume of the infarct core and the volume of the total perfusion defect (15.7% and 5.8%, respectively) compared to manual post-processing (31.0% and 12.2%, respectively). Automated post-processing yielded lower coefficients of variation for PCT values (11.3% for CBV, 9.7% for CBF, and 9.5% for MTT) compared to manual post-processing (23.7% for CBV, 32.8% for CBF, and 16.7% for MTT).ConclusionAutomated post-processing of PCT data improves interobserver agreement in measurements of CBV, CBF and MTT, as well as volume of infarct core and penumbra.

Angiographie par Résonance Magnétique dans l’artériopathie distale des membres inférieurs : peut-on se passer d’une séquence multiphase (TRICKS) ?

To demonstrate the added diagnostic value of time-resolved imaging of contrast kinetics (TRICKS) in the evaluation of lower limb arteries compared to standard 3 level MRA with stepping table method. Forty patients (30% diabetics) with lower extremity peripheral arterial disease (87.5% with chronic ischemia) underwent standard contrast MRA including TRICKS of the distal arteries. Five arterial segments were defined per leg, and 395 arterial segments were compared (one patient with amputation). Two reviewers evaluated the quality of arterial imaging, presence of venous return and degree of stenosis per segment. The degree of interobserver agreement for arterial stenosis measurement was calculated. More arterial segments could be analyzed on the TRICKS sequence (good or excellent analysis in 63.03%-66.32% of arterial segments compared to 41.51%-47.08% on routine MRA). There was less venous contamination on TRICKS images (25.57% to 27.60% gain). The degree of interobserver agreement was superior with TRICKS compared to standard MRA (kappa 0.85 vs 0.69). The TRICKS sequence can be added to standard MRA for pre-therapeutic evaluation of distal arteries in patients with peripheral arterial disease, especially with chronic ischemic with rest pain and/or trophic changes.

Capillary Refill Time in Adults Has Poor Inter-Observer Agreement

ObjectivesCapillary refill time (CRT) has been taught as a rapid indicator of circulatory status but to be a useful clinical test, CRT needs to be reproducible when performed by another health care worker. No inter-rater agreement studies have been reported for adult patients. The aim of this study was to determine the inter-observer reliability of CRT in a sample of adult emergency department (ED) patients. Methods This prospective observational study included clinically stable ED patients with a variety of conditions from two community EDs. A doctor and a nurse each measured CRT by estimation to the nearest half-second using a standard method on each patient. They were blinded to each other's measurements. The primary outcome of interest was inter-rater agreement. Secondary outcome was agreement in classification as normal or abnormal according to accepted definitions. Data was analysed using bias plot analysis, correlation, absolute percent agreement and kappa analysis. Results Totally, 209 patients were enrolled; 51% were female and 86% were Caucasian. Median CRT was 2 seconds (95% CI 2–2.35 seconds). The mean difference between measurements by the different observers was 0 second, however the 95% limits of agreement were very wide (–1.7 to +1.9 seconds). Agreement was 70% for classification of ‘normal’ or ‘abnormal’ using the 2-second definition of normal, with a kappa of 0.38. Conclusion Interobserver agreement in measurement of CRT was poor in adult subjects with wide limits of agreement. This is a serious threat to the appropriateness of this test for use in clinical practice.

Reproducibility of the Histological Diagnosis of Cervical Dysplasia Among Pathologists From 4 Continents

The reliable histological diagnosis of cervical squamous intraepithelial lesions (SILs), especially low-grade SIL, is known to be problematic. Poor diagnostic reproducibility can complicate studies addressing its appropriate management. As part of an international study comparing expectant management of histologically proven low-grade SIL with immediate loop electrocautery excisional procedure, this study was carried out to assess interobserver agreement on the histological diagnosis of SILs among a group of 22 pathologists from 5 countries and the intraobserver reliability among a subset of 7 Canadian pathologists. Fifty-six histological slides from colposcopically obtained cervical biopsies were circulated to each of the 22 pathologists. To assess intraobserver reliability, 7 Canadian pathologists assessed 40 of the slides once and 16 of the slides twice. Kappa values were used to measure interobserver agreement with an overall kappa value of 0.61 (95% confidence interval, 0.60-0.62) corresponding to moderate reliability. The weighted kappa values for interobserver agreement ranged from 0.46 to 0.88 (median, 0.79). The intraobserver reliability of 7 Canadian pathologists ranged from substantial to excellent based upon the weighted kappa values ranging from 0.62 to 0.94 (median, 0.72). This degree of reliability is comparable to that found in similar studies. In an individual case, there can be considerable disparity in diagnosis that can result in disparate management strategies. This adds a layer of complexity to any trial that attempts to assess optimal treatment strategies or the natural history of this disease.

Differentiating Atrioventricular Nodal Reentrant Tachycardia from Junctional Tachycardia: Novel Application of the Delta H‐A Interval

Junctional tachycardia (JT) and atrioventricular nodal reentrant tachycardia (AVNRT) can be difficult to differentiate. Yet, the two arrhythmias require distinct diagnostic and therapeutic approaches. We explored the utility of the delta H-A interval as a novel technique to differentiate these two tachycardias. We included 35 patients undergoing electrophysiology study who had typical AVNRT, 31 of whom also had JT during slow pathway ablation, and four of whom had spontaneous JT during isoproterenol administration. We measured the H-A interval during tachycardia (H-A(T)) and during ventricular pacing (H-A(P)) from the basal right ventricle. Interobserver and intraobserver reliability of measurements was assessed. Ventricular pacing was performed at approximately the same rate as tachycardia. The delta H-A interval was calculated as the H-A(P) minus the H-A(T). There was excellent interobserver and intraobserver agreement for measurement of the H-A interval. The average delta H-A interval was -10 ms during AVNRT and 9 ms during JT (P < 0.00001). For the diagnosis of JT, a delta H-A interval >or= 0 ms had the sensitivity of 89%, specificity of 83%, positive predictive value of 84%, and negative predictive value of 88%. The delta H-A interval was longer in men than in women with JT, but no gender-based differences were seen with AVNRT. There was no difference in the H-A interval based on age <or= 60 years. The delta H-A interval is a novel and reproducibly measurable interval that aids the differentiation of JT and AVNRT during electrophysiology studies.